1. Institute of Pathology; University Hospital of Essen; University of Duisburg-Essen; Essen Germany
2. Department of Gastroenterology and Hepatology; University Hospital of Essen; University of Duisburg-Essen; Essen Germany
3. Institute of Pathology; University Hospital of Düsseldorf; Heinrich Heine University of Düsseldorf; Düsseldorf Germany
4. Department of General, Visceral and Transplantation Surgery; University Hospital of Essen; University of Duisburg-Essen; Essen Germany